Food processing apparatus

ABSTRACT

The lid support member for the lid of a high speed food processing apparatus supports a mixing baffle blade through the center of the lid. The mixing baffle blade drive shaft is hollow for introducing liquids into the mixing bowl directly over the food processing blades.

BACKGROUND OF THE INVENTION

This invention relates to high speed food processing machines in which avertical drive shaft supports and drives food processing blades withinan upwardly open food containing bowl. The bowl, which is closed by alid during food processing, is pivoted for pouring its contents.Typically, a powerful motor on the bottom of the bowl rotates the driveshaft, and a mixing baffle blade is supported through the lid forrotation along and around the inside surface of the bowl for removingand returning foodstuffs from the side of the bowl to the vicinity ofthe food processing blades for further processing. The blades areremovable and interchangeable, so that the blade or other toolconfigurations may be matched to the processing needs at hand. Machinesof this type are highly effective in processing foods, and are so fast(many operations being performed in less than a minute), that the actualprocessing time is but a small part of the total "turn around" time.That is, it usually takes longer to load and unload the machine than toprocess the food once it is in the machine.

It is sometimes desirable to introduce ingredients into the bowl whilethe foodstuffs are being processed. Preferably, these ingredients shouldbe distributed uniformly into the main body of the foodstuffs, and thereshould be no splashing or throwing of material back out of the bowl. Fordoing this in prior art devices, they have commonly been stopped, thebaffle blade and its drive shaft removed, and then the baffle bladedrive shaft hole in the lid is used for this purpose. However, thisrequires stopping the apparatus, removing a possibly messy baffle blade,and then operating the apparatus without the benefit of the baffle bladewhile the ingredients are being added.

SUMMARY OF THE INVENTION

Briefly, the present invention overcomes the above prior artdifficulties by providing for introducing ingredients as the food isbeing processed, without having to remove the mixing baffle blade. Thisis accomplished by providing a hollow drive shaft for the mixing baffleblade. The drive shaft is open at both ends so that it connects throughthe center of the lid for introducing ingredients into the mixing bowldirectly over the food processing blades and drive shaft. Theingredients are then spun from the top of the drive shaft in anessentially uniform pattern across the top of the main body offoodstuffs within the bowl.

It is therefore an object of the present invention to provide animproved apparatus for high speed processing of foodstuffs; an apparatuswhich includes a hollow mixing baffle blade drive shaft in the center ofthe lid for introducing liquids into the mixing bowl directly over thefood processing blades and drive shaft; and to accomplish the aboveobjects and purposes in a versatile and durable configuration readilysuited to processing a wide variety of food products.

Other objects and advantages of the invention will be apparent from thefollowing description, the accompanying drawings and the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially sectioned front view of a food processingapparatus incorporating the features of the present invention;

FIG. 2 is a side view of the FIG. 1 apparatus with a food receiving panand cart next to it, the food processing apparatus being shown in solidlines in its operating position, the raised lid position being shown inphantom, and the pouring position of the apparatus being shown inphantom, illustrating the raised pouring height;

FIG. 3 is a plan view of the apparatus;

FIG. 4 is a partially sectioned, fragmentary plan view, taken on line4--4 of FIG. 1, illustrating the pivot and counterbalance for the lid;

FIG. 5 is a fragmentary cross sectional view, taken on line 5--5 in FIG.3, showing the hollow mixing baffle blade drive shaft passing throughthe lid and lid support;

FIG. 6 is a cross sectional view of the stand arm in which thecounterbalance spring assembly is located, the view being in thedirection looking from left to right in FIG. 1, but illustrating thepositions of the parts when the bowl is tilted to the pouring (phantomline) position of FIG. 2;

FIG. 7 is an enlarged, fragmentary, partially sectioned showing of aportion of the counterbalance spring assembly as seen in FIG. 6;

FIG. 8 is an enlarged detail of the lid scraper as seen in FIG. 1;

FIG. 9 is a cross sectional view taken on line 9--9 in FIG. 8;

FIG. 10 is a plan view of the lid scraper as seen looking downwardly inFIG. 8;

FIG. 11 is a partially sectioned, enlarged fragmentary view showingdetails of the drive shaft, blade mount, and wedge lock;

FIG. 12 is a bottom view of the wedge lock cap;

FIG. 13 is a cross sectional view taken on line 13--13 of FIG. 11;

FIG. 14 is a cross sectional view taken on line 14--14 of FIG. 11;

FIG. 15 is a cross sectional view of a food basket located within thebowl; and

FIG. 16 is a fragmenatary plan view of the FIG. 13 basket.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The food processing apparatus 20, illustrated in FIG. 1, includes astand 22 having hollow, vertically extending arms 23a and 23b. Arms 23aand b support a bowl 25 and drive motor 26 through shafts 28a and 28bwhich are journaled, respectively, in arms 23a and b. Shafts 28a and bare thus free to pivot and rotate in arms 23a and b, and define ahorizontal axis of rotation for the bowl 25 and motor 26. Shafts 28a andb are received in bores 31 in a motor and bowl support brace 32extending between arms 23a and b. Shafts 28a and b are pinned by pins 33in brace 32 to cause the shafts and brace to rotate together as a unit.

When in the food processing position, the bowl is upright (as shown insolid lines in FIG. 2) and upwardly open, with its upper edge 34defining a horizontal plane. Bowl 25 is substantially radiallysymmetrical, defining a figure of rotation about the vertical centerline of the bowl. The drive shaft 35 (FIG. 11) of motor 26 enters bowl25 through its bottom and is coaxial with the center line of the bowl.As should also be clear from FIG. 2, the horizontal or pouring axisdefined by shafts 28a and b is located between the center line of thebowl and the forward or pouring edge of the bowl, on which there is apouring lip 37. By positioning the horizontal axis forwardly, a greaterpouring height is provided than would occur if the axis passed throughthe center line of the bowl, as in many prior art machines. The greaterpouring height provides sufficient clearance for conventional receivingpans such as the pan 38 on the cart 39 illustrated in FIG. 2.

The food (not shown) is processed within bowl 25 by one or more foodprocessing tools, such as blades 40, which are carried on a tool orblade mount 42. Mount 42 is a hollow shaft which fits onto the driveshaft 35 (FIG. 11) and has a hollow square coupling 43 at its base whichfits driveably onto a matching square driving portion 44 on the driveshaft 35, at the bottom of the bowl (FIGS. 11 and 14). The couplingbetween the drive shaft and blade mount transmits the drive torque fromthe drive shaft to the mount and to the blades 40. Blade mount 42extends upwardly, terminating at an upper end 46 adjacent the upper end47 of drive shaft 35. The blade mount is readily removed and replaced bysliding it vertically onto and off the drive shaft, over the upper end47 thereof.

FIGS. 11-13 illustrate details of the manually operable wedge lock forsecuring and releasing the blade mount 42 and food processing blades 40on the drive shaft 35. As illustrated, the upper end 47 of drive shaft35 terminates in a cylindrical boss 50, the axis of which is coincidentwith the axis of rotation of the drive shaft 35. Boss 50 thus defines avertically oriented cylindrical surface 51. The upper end 46 of theblade mount 42 is similarly provided with a cylindrical bore 55 having asubstantially vertical axis which, however, is not coincident with theaxis of rotation of drive shaft 35, and is therefore eccentric withregard to cylindrical boss 50. As a result, the vertically orientedcylindrical surface 56 on the inside of bore 55, which is spaced fromsurface 51, is eccentric with regard thereto. Further, as illustrated,surface 51 of boss 50 is contained within the cylindrical volume definedby surface 56 of bore 55. The surfaces 51 and 56 are surfaces ofrotation, and the space 60 (FIG. 11) between them is a radiallyeccentric space. Due to the symmetries which are consequent to figuresand surfaces of rotation (their axes being vertical), the radiallyeccentric space 60 is a substantially symmetrical space about a radialbisection line passing through the respective axes of rotation of thesurfaces 51 and 56. (This can be seen in FIG. 13, where the top andbottom halves of the figure are symmetrical about a horizontal bisectionline).

Surfaces 51 and 56, along with the radially eccentric space 60 whichthey define, are important parts of the wedge lock by which the blademount 42 is secured onto the drive shaft 35. The remainder of the wedgelock is carried in a cap 61 having a manually engageable head 62 on itstop side and a wedging portion 65 extending from its bottom side.Wedging portion 65 has an inner cylindrical surface 66 of the samedimension as, and complementary to, the cylindrical surface 51 on boss50, and an outer surface 67 of the same dimension as, and complementaryto, that of surface 56 inside the cylindrical bore 55 on the upper end46 of blade mount 42. Wedging portion 65 is thus dimensioned forreception in, and is substantially complementary to, the radiallyeccentric space 60 on the upper ends 46 and 47 of mount 42 and driveshaft 35. Therefore, to secure the blade mount 42 on shaft 35 after itis positioned thereon, the operator grips the cap head 62, positionswedging portion 65 opposite space 60, and inserts the wedging portioninto space 60. The cap 61 is next rotated sharply either to the left orto the right. This causes surfaces 66 and 67 to interfere with surfaces51 and 56 as they move relative to one another and as the wedgingportion is shifted to force the larger portions thereof into thenarrower portions of the eccentric space 60. This wedge interferencejams the blade mount coupling 43 and the drive shaft driving portion 44into tight engagement with one another to secure the mount 42 and blades40 thereon onto the drive shaft 35.

While boss 50 has been illustrated with its axis coincident with theaxis of rotation of drive shaft 35, it should be clear that the axes ofboss 50 and cylindrical bore 55 could readily be exchanged, with asimilar modification to surfaces 66 and 67 on wedging portion 65. Thiswould still produce an upwardly open, radially eccentric space betweenthe upper ends 46 and 47 of the blade mount 42 and drive shaft 35.Further analysis will make it clear that the wedge lock of thisinvention does not require surfaces which are directly opposed to (i.e.facing) one another. The upper end 47 of drive shaft 35, for example,could be provided with a bore (which might even be other thancylindrical) and the outside of the upper end 46 of blade mount 42 couldbe provided with a surface (which likewise need not be cylindrical)which would be eccentric with regard to one another. It is sufficientthat the two upper ends 46 and 47 have surfaces which are spaced fromone another, eccentric with regard to one another, preferably vertical,one geometrically inside the other, and both engageable by complementarysurfaces on the cap 61. When so configured and properly spaced, rotationof the cap will jam the mount and drive shaft together as theeccentricities on the cap surfaces are rotated out of alignment with theeccentric drive shaft and blade mount surfaces. It should also be notedthat the blade mount and drive shaft may be jammed together elsewherethan at the bowl bottom. All that is required is a region therebetweenwhich is spaced closely enough that the eccentric surfaces can jam themtogether when the cap is rotated.

The top of apparatus 20 is closed by a cover system which includes a lid70 supported at its center by a rigid support arm 71 pivoted at 72 toone side of bowl 25. Arm 71 swings on pivot 72 from a lowered, closedposition (FIG. 1), to a raised, open position (shown in phantom in FIG.2). The weight of the lid and arm is counterbalanced by a counterbalancespring 73 (FIG. 4) forming a part of pivot 72, and operating between thearm 71 and bowl 25. The end of arm 71 is latched in the down position bya rotary latch 76 turned by a handle 77 to capture the end of arm 71thereadjacent. Latch 76 engages arm 71 in a manner which firmly pressesarm 71 downwardly against lid 70 to secure and seal the lid against thetop edge 34 of bowl 25. For example, in one embodiment latch 76 drivesarm 71 3/16 of an inch below the point at which the lid 70 engages theedge 34 of bowl 25.

Lid 70 is preferably made of transparent plastic material so that themachine user can view the contents of the closed bowl without the needto perforate the lid. Perforations weaken the lid structure so thatsealing forces are not transmitted uniformly to the perimeter of thelid, and perforations also allow foodstuffs to be splashed out of thebowl.

However, such a lid must also seal effectively over a wide range ofworking conditions and applications. That is, if the fit between the lid70 and the bowl edge 34 requires critical adjustment of the latch 76, itwill be more expensive to calibrate during manufacture and will requiremore frequent adjustment in service. To meet these several needs, lid 70has a configuration which causes it to act like a spring when arm 71 isforced downwardly against it by latch 76. More particularly, the centralportion 80 of the lid is formed as a substantially flat disc and servesas a flexible spring-like member (somewhat like a drumhead). The outerportion 81 of the lid surrounds and extends from and beyond the central,flexible portion 80. Portion 81 is a ring which slopes downwardly todefine an annular portion of a cone. The geometry of this coneinherently stiffens portion 81 so that it does not flex from thepressure of arm 71, but transmits that force directly to the outer edgeof the lid. By making the central portion 80 of the lid smaller, thespringiness can be effectively stiffened, and vice versa.

The lid 70 terminates in a rim 85 on the outer edge of the stiff, outerring 81. Rim 85 is dimensioned for engaging the upper edge 34 of themixing bowl, and defines a substantially planar annulus which overliesthis edge of the bowl when the cover system is closed. Rim 85 isslightly larger than necessary in order to accommodate lateralmisregistration between the lid 70 and top 34 of the bowl 25, thusproviding additional tolerance. The tolerances are so great, in fact,that no sealing gasket is needed between the lid and the bowl. It shouldalso be noted that the central, flexible disc portion 80 will tolerate aslight twist in the support arm 71 if the arm, for some reason, is notprecisely parallel with the plane defined by the top edge 34 of thebowl.

High speed food processing machines of this type usually have a mixingbaffle blade such as blade 95. Such blades are supported and mountedthrough the top of the apparatus for rotation about an axis parallel tothe axis of the drive shaft 35. The mixing baffle blade is positionedfor rotation along and around the inside surface of the bowl forremoving and returning foodstuffs from the side of the bowl to thevicinity of the food processing blades 40. As illustrated, the presentinvention incorporates such a mixing baffle blade 95, which is supportedon a support 96, such as a beam of stainless steel. The support 96cantilevers blade 95 from a central drive shaft 98 which is supportedfor rotation in the lid support arm 71 and passes through the centraldisc portion 80 of the lid to the interior. A handle and crank assembly99 is attached to the top or outer end of drive shaft 98 for manuallyrotating the mixing baffle blade 95 during processing of the foodstuffswithin the apparatus 20.

Drive shaft 98 may be hollow, as illustrated in FIG. 5, and open in thetop and bottom thereof to provide a passageway through the center of thelid 70 from outside the bowl 25 into the interior thereof. This providesfor introducing liquids into the mixing bowl directly over the foodprocessing blades 40 and drive shaft 35 while the motor 26 is beingoperated. Cap 61 effectively shields the hollow drive shaft 98 fromfoodstuffs which might otherwise be thrown out. Further, as the liquidsare introduced through shaft 98, cap 61 acts as a spinner to fling theliquids outwardly and uniformly across the foodstuffs as they are beingprocessed. It has been found that better and more uniform processingresults when liquids are introduced in this manner.

A lid scraper 100 is mounted on an extension portion 104 of the scraperblade support beam 96 for rotation therewith in scraping contact withthe inner surface of the lid 70. Lid scraper 100 includes a scraperblade 101 and a gripping body 102. Gripping body 102 is a resilientportion which is dimensioned for fitting onto and frictionally engagingextension portion 104. In the preferred embodiment, extension portion104 extends in a radially opposite direction from the main portion 105of the support, the baffle blade 95 being attached to the main portion105. Then, as the mixing baffle blade 95 is rotated around bowl 25 bythe handle and crank assembly 99, the lid scraper blade 101simultaneously removes and returns foodstuffs from the lid inner surfaceto the body of foodstuffs within the bowl for better and more uniformprocessing of the foodstuffs. When processing is concluded, the lidscraper blade 101 removes food products from the lid 70 before it isopened to reduce dripping from the lid. In addition, when the lid istransparent, the scraper clears foodstuffs for easier viewing.

Preferably, the handle and crank assembly 99 and the extension portion104 of the support 96 extend in radially opposite directions from themain portion 105 of the support on which the mixing baffle blade 95 issuspended. The extension portion 104 and handle and crank assembly 99are sized and positioned to counterbalance the mixing baffle blade 95and the main portion 105 of the support 96 to reduce or even eliminatethe tendency of the mixing baffle blade 95 to rotate, under the pull ofgravity, when the lid is open and the apparatus 20 is tilted forremoving the food products. Further, the lid scraper 100 is shaped to bebiased against the lid with sufficient frictional force to act as abrake. Thus, the lid scraper 100 also helps to prevent the mixing baffleblade 95 and support 96 from freely rotating under the influence ofgravity when its axis of rotation is shifted from the vertical.

When the apparatus is tilted, as shown in phantom in FIG. 2, to removeingredients from the bowl 25, the weight of the motor 26 resists tiltingof the bowl. The motor is therefore counterbalanced for easier pouringand better control of the foodstuffs when the bowl is tilted. Such acounterbalance is contained and enclosed in arm 23a so that it isprotected from exposure to foodstuffs outside the machine, and viceversa, for purposes of sanitation. The counterbalance spring assembly110 is attached to pivot shaft 28a at the upper end of arm 23a andoperates against a stop 112 farther down in arm 23a. As may be seen inFIG. 6 (which shows the spring assembly when the bowl has been fullytilted), the counterbalance spring assembly 110 is thus operativebetween arm 23a and shaft 28a to help rotate the shaft in a clockwisedirection (as shown in FIG. 6) to counterbalance the motor 26 duringtilting. Control of bowl 25 during tilting and pouring is also aided bya brake 113 in arm 23b. Brake 113 is operated by a brake handle 114 tocontrol rotation of shaft 28b, and hence bowl 25, relative to arm 23b.

Counterbalance spring assembly 110 includes a crank 115 which is fixedto shaft 28a by a bolt 116. A yoke 117 is pivoted at 118 to crank 115 onthe end of the crank opposite shaft 28a. Yoke 117 carries a collar 119on the end of the yoke opposite crank 115 and pivot 118, and a tube 120is fixed to and extends from the yoke and collar in a downward directionaway from pivot 118. A guide rod 122 is received in tube 120 and is freeto slide upwardly and downwardly through the tube and the collar 119,but is not permitted to slide downwardly out of the tube, due to a stopnut 123 which is threaded onto the top end of rod 122 above collar 119.In other words, nut 123 establishes a lower limit of travel for rod 122.

The lower end of rod 112 opposite collar 119 passes through a pad 125. Astop nut 126 threaded on the bottom of guide rod 122 below pad 125establishes a lower limit of movement for pad 125 on rod 122, orconversely, nut 126 establishes an upper limit of travel for guide rod122 through pad 125. Otherwise, rod 122 and pad 125 are free to sliderelative to one another.

Finally a spring 130 is mounted on guide rod 122 in compression betweencollar 119 and pad 125, so that spring 130 normally spreads the pad 125and collar 119 until they reach stop nuts 123 and 126. Nuts 123 and 126and rod 122 then maintain the spring 130 in compression.

When in operative position within arm 23a, pad 125 rests on stop 112,which is illustrated as two rods or pins (FIGS. 1 and 6) passing througharm 23a and nesting pad 125 therebetween. As illustrated by the arrowsin FIG. 6, crank 115 is positioned to move yoke 117 and collar 119 awayfrom pad 125 when the bowl 25 is rotated from its upright, foodprocessing position to its tilted, pouring position, and vice versa. Asthe bowl is returned to its upright position from the fully tiltedposition in FIG. 6, collar 119 approaches pad 125, the tension on rod122 is relieved, spring 130 is further compressed, and the pressure ofspring 130 operates between stop 112 (through pad 125) and shaft 28a(through collar 119, yoke 117, and crank 115). The reduction of thedistance between collar 119 and pad 125 frees rod 122 to movetherebetween, within the limits set by nuts 123 and 126. Pad 125 guidesrod 122 so that the rod will keep the spring 130 thereon. Pad 125 alsoguides rod 122 as it slides downwardly under the pull of gravity. Thecounterbalance spring assembly 110 is thus compact, can be whollycontained within arm 23a, can be easily inserted into the arm, and canbe pretensioned (due to rod 122).

A start switch 132 and stop switch 133 (FIG. 3) start and stop theapparatus 20. A mode switch 134 controls whether the operation iscontinuous (when switch 134 is in the "run" position) or intermittent(when in the "jog" position). When switch 134 is in the "jog" position,machine 20 stops as soon as start switch 132 is released. In addition tostop switch 133, the apparatus may be stopped by releasing latch 71, bytilting the bowl, or by placing switch 134 in the "jog" position.

FIGS. 15 and 16 illustrate an optional food basket 135 which can beinserted into bowl 25 for quickly and easily processing foodstuffswithin the basket 135. Prior art food baskets, however, have been madeof metal, presumably to provide sufficient strength to preserve theshape of the basket. However, metals are ductile, and once bent ordented, are difficult to restore to their original shape. This isespecially troublesome where clearances are close, as here. The presentinvention, therefore, uses baskets 135 which are made of flexible,non-ductile, plastic material. While the baskets are not sufficientlyrigid to retain their shapes, they are particularly resistant topermanent denting, bending, or stretching. Each basket is then formed sothat its exterior surface conforms closely to the interior surface ofthe bowl. Since the basket fits the bowl interior very closely, therigid bowl will support the basket structurally and restore the basketto its proper bowl matching shape. In the present invention, therefore,it is recognized that the food basket 135 does not have to be able tohold itself in proper shape, and can be much more resistant to abuse, ifit is sized for cooperative interaction with the bowl 25.

As may be seen, therefore, the present invention provides numerousadvantages. The lid is so structured and supported that transparentmaterials may be used for better and easier viewing of the contents ofthe food apparatus, yet wide tolerances are provided. The mixing baffleblade is counterbalanced and carries a lid scraper for removingfoodstuffs from the inner surface of the lid to improve the uniformityof the food processing, reduce the tendency of the lid to drop whenopened, and provide for viewing the contents when the lid istransparent. The lid scraper also acts as a brake to reduce thelikelihood that the mixing baffle blade will move when the lid isopened. Pouring or removing the processed foodstuffs from the apparatusis facilitated through a higher pouring height and a wholly containedcounterbalance system. Insertion and removal of the food processingblades is a simple, quick operation involving but a short twist of thecap 61 in either direction to lock or unlock the mixing blades on thedrive shaft. Ingredients can be added during processing through thehollow mixing baffle blade drive shaft, and the ingredients areuniformly distributed and processed without splash back of ingredients.If the foodstuffs are to be supported in a separate food basket, aflexible, non-ductile basket can be used to reduce the likelihood ofdamage from bending or denting of the basket.

While the form of apparatus herein described constitutes a preferredembodiment of this invention, it is to be understood that the inventionis not limited to this precise form of apparatus, and that changes maybe made therein without departing from the scope of the invention.

What is claimed is:
 1. In an apparatus for processing foodstuffs,including a mixing bowl having a drive shaft extending into the bowlthrough the bottom center thereof, a motor mounted outside the bowl andconnected to rotate the drive shaft, food processing blades mountable onthe drive shaft within the bowl for processing foodstuffs therein whenthe motor is operated, a cover system including a lid for closing thetop of the bowl, and a mixing baffle blade and support mounted throughthe center of the lid for rotation along and around the inside surfaceof the bowl for removing and returning foodstuffs from the side of thebowl to the vicinity of the food processing blades for furtherprocessing thereby, the improvement comprising means defining a hollowdrive shaft for said mixing baffle blade and support connecting throughthe center of the lid and being open in the top and bottom thereof forintroducing liquids into the mixing bowl directly over the foodprocessing blades and drive shaft while the motor is being operated..Iadd.
 2. The combination of claim 1 further comprising a cap on the topof the drive shaft beneath said hollow drive shaft. .Iaddend..Iadd. 3.The combination of claim 2 wherein said cap has a diameter greater thanthat of said open bottom of said hollow drive shaft for spinning andflinging the liquids across the top of the main body of foodstuffswithin the bowl when introduced through said hollow drive shaft..Iaddend..Iadd.
 4. The combination of claim 2 or 3 further comprisingmeans positioning said cap on the drive shaft sufficiently close to saidhollow drive shaft to prevent splash back of ingredients therethroughand to shield said hollow drive shaft from foodstuffs which mightotherwise be thrown out. .Iaddend.